Related Experiment Video

Updated: Feb 28, 2026

Purification of the Membrane Compartment for Endoplasmic Reticulum-associated Degradation of Exogenous Antigens in Cross-presentation
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Opposing roles for SNAP23 and SNAP25 in mediating MR1 trafficking and antigen presentation

Se-Jin Kim1,2, Corinna A Kulicke1, David M Lewinsohn1,3

  • 1Division of Pulmonary, Allergy, and Critical Care Medicine, Oregon Health & Science University, Portland, OR 97239, USA.

Biorxiv : the Preprint Server for Biology
|February 27, 2026
PubMed

Insights

Synapse-associated protein 23 (SNAP23) enhances MR1 antigen presentation, while SNAP25 suppresses it. This reveals opposing roles for SNAP proteins in MR1 trafficking and MAIT cell activation during microbial infections.

Area of Science:

  • Immunology
  • Cell Biology
  • Microbiology

Background:

  • The Major Histocompatibility Complex (MHC) class I-related protein 1 (MR1) presents microbial metabolites to mucosal-associated invariant T (MAIT) cells.
  • MR1 trafficking involves SNARE proteins like Syntaxin 4 and VAMP 4.
  • Synapse-associated proteins (SNAPs) are crucial for SNARE complex formation and function.

Purpose of the Study:

  • To investigate the role of SNAPs in MR1-mediated antigen presentation.
  • To determine how SNAP family proteins influence MR1 trafficking and MAIT cell activation.

Main Methods:

  • Investigated SNAP homologs' function in MR1 presentation.
  • Assessed the impact of SNAP23 and SNAP25 on MR1 trafficking during infection with *Mycobacterium tuberculosis* (Mtb).
  • Evaluated MR1 presentation of antigens from Mtb, *Mycobacterium avium*, and *Candida albicans*.

Main Results:

  • SNAP23 positively regulates MR1 presentation of Mtb-derived antigens and MR1-containing vesicle numbers.
  • SNAP25 inhibits MR1 presentation for Mtb, *M. avium*, and *C. albicans*.
  • SNAP23 and SNAP25 exhibit opposing functions in MR1 antigen presentation.

Conclusions:

  • SNAP23 and SNAP25 play distinct, opposing roles in MR1 antigen presentation to MAIT cells.
  • This study elucidates the regulatory mechanisms of MR1 trafficking by SNAP proteins during microbial infections.

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